Alpha Volantis

Alpha Volantis (Alpha Vol), Latinized from α Volantis, is a binary star[12] system located in the southern constellation Volans. It has an apparent visual magnitude of +4.00, which is bright enough to be seen with the naked eye. Based upon parallax measurements made with the Hipparcos spacecraft, it is located at a distance of 125 light years from the Sun. As of 2010, the two components of this system had an angular separation of 0.0318″ along a position angle of 286.9°. The magnitude difference between the two components is 0.1.[13] It is considered a member of the Sirius supercluster.[5]

α Volantis
Location of α Volantis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Volans
Right ascension 09h 02m 26.79592s[1]
Declination −66° 23′ 45.8727″[1]
Apparent magnitude (V) +4.00[2]
Characteristics
Spectral type kA3hA5mA5 V[3]
U−B color index +0.13[2]
B−V color index +0.14[2]
Astrometry
Radial velocity (Rv)+4.9[4] km/s
Proper motion (μ) RA: −2.00[1] mas/yr
Dec.: +95.51[1] mas/yr
Parallax (π)26.11 ± 0.12 mas[1]
Distance124.9 ± 0.6 ly
(38.3 ± 0.2 pc)
Absolute magnitude (MV)+1.60[5]
Orbit[6]
Period (P)0.652 ± 0.001 yr
Semi-major axis (a)0.0321 ± 0.0013″
Eccentricity (e)0.041 ± 0.038
Inclination (i)101.9 ± 2.3°
Longitude of the node (Ω)105.3 ± 1.4°
Periastron epoch (T)2015.593 ± 0.063
Argument of periastron (ω)
(secondary)		248.5 ± 34.2°
Details
Mass1.87[7] M☉
Radius1.9[8] R☉
Surface gravity (log g)4.09[3] cgs
Temperature8,198[3] K
Metallicity [Fe/H]+0.19[3] dex
Rotational velocity (v sin i)30.6±0.4[9] km/s
Age427+183
−377[10] Myr
Other designations
CPD−65°1065, FK5 343, GJ 333.3, HD 78045, HIP 44382, HR 3615, SAO 250422.[11]
Database references
SIMBADdata

The primary component is an Am star with a stellar classification of kA3hA5mA5 V.[3] This notation indicates the star has the weak calcium II K-line of an A3 star, and the hydrogen and metallic lines of an A5 star.[14] It has an estimated age of 427 million years.[10] In 1992, it was found to be emitting an infrared excess, suggesting the presence of a circumstellar disk of dust.[15] However, subsequent observations have not confirmed this.[16]

References
  1. van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M.
  3. Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
  4. Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veröff. Astron. Rechen-Inst. Heidelb, Astronomisches Rechen-Institut Heidelberg, 35 (35): 1, Bibcode:1999VeARI..35....1W.
  5. Eggen, Olin J. (August 1998), "The Sirius Supercluster and Missing Mass near the Sun", The Astronomical Journal, 116 (2): 782–788, Bibcode:1998AJ....116..782E, doi:10.1086/300465.
  6. Tokovinin, Andrei; Mason, Brian D.; Mendez, Rene A.; Horch, Elliott P.; Briceño, Cesar (2019), "Speckle Interferometry at SOAR in 2018", The Astronomical Journal, 158 (1): 48, arXiv:1905.10436, Bibcode:2019AJ....158...48T, doi:10.3847/1538-3881/ab24e4, S2CID 197431463
  7. David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
  8. Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (Third ed.), 367 (2): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
  9. Díaz, C. G.; et al. (July 2011), "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum", Astronomy & Astrophysics, 531: A143, arXiv:1012.4858, Bibcode:2011A&A...531A.143D, doi:10.1051/0004-6361/201016386, S2CID 119286673.
  10. Song, Inseok; et al. (February 2001), "Ages of A-Type Vega-like Stars from uvbyβ Photometry", The Astrophysical Journal, 546 (1): 352–357, arXiv:astro-ph/0010102, Bibcode:2001ApJ...546..352S, doi:10.1086/318269, S2CID 18154947.
  11. "alf Vol". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-09-02.{{cite web}}: CS1 maint: postscript (link)
  12. Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  13. Hartkopf, William I.; et al. (2012), "Speckle Interferometry at SOAR in 2010 and 2011: Measures, Orbits, and Rectilinear Fits" (PDF), The Astronomical Journal, 143 (2): 19, Bibcode:2012AJ....143...42H, doi:10.1088/0004-6256/143/2/42, 42, archived from the original on June 29, 2017.
  14. Gray, Richard O.; Corbally, Christopher J. (2009), Stellar Spectral Classification, Princeton, New Jersey: Princeton University Press, p. 309, ISBN 978-0-691-12511-4.
  15. Cheng, K.-P.; et al. (September 1992), "Newly identified main-sequence A stars with circumstellar dust", Astrophysical Journal, Part 2, 396 (2): L83–L86, Bibcode:1992ApJ...396L..83C, doi:10.1086/186522.
  16. Gáspár, András; et al. (May 2013), "The Collisional Evolution of Debris Disks", The Astrophysical Journal, 768 (1): 29, arXiv:1211.1415, Bibcode:2013ApJ...768...25G, doi:10.1088/0004-637X/768/1/25, S2CID 119295265, 25.
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